十八、平铺+将ListBoxitem的宽度设定为ListBox的三分之一

Silverlight 怎么把图片平铺？

1<StackPanel Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Orientation="Horizontal">
           
        </StackPanel>

 2           <ListBox.ItemsPanel>
                <ItemsPanelTemplate>
                    <controlsToolkit:WrapPanel Orientation="Horizontal"/>
                </ItemsPanelTemplate>
            </ListBox.ItemsPanel>

如何将ListBoxitem的宽度设定为ListBox的三分之一？ 我已经写了一个Converter,可是在XAML中如何写呢 总也运行不对，请教各位大大

里面加一个Grid 然后按比例 分为三列 让Item在 Grid.Row =2;

<ListBox> <ListBox.ItemTemplate> <DataTemplate> .....</DataTemplate> </ListBox.ItemTemplate>            <ListBox.ItemsPanel>                 <ItemsPanelTemplate>                     <controlsToolkit:WrapPanel Orientation="Horizontal"/>                 </ItemsPanelTemplate>             </ListBox.ItemsPanel>             <ListBox.ItemContainerStyle>                 <Style TargetType="ListBoxItem">                     <Setter Property="Width" Value="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=ListBox, AncestorLevel=1}, Path=Width, Converter={StaticResource WidthConverter}, ConverterParameter=4}"/>                 </Style>             </ListBox.ItemContainerStyle>             <!--<i:Interaction.Behaviors>                 <Behaviors:SynchronizeSelectedItems Selections="{Binding SelectedOption}"/>             </i:Interaction.Behaviors>-->

        </ListBox>

不能使用固定列数，因为是需要根据不同的情况，设定为2，3，4列的

那 你的 1/3如何取呢 ：给Converter传一个参数